Note: Descriptions are shown in the official language in which they were submitted.
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ELECTRONIC GAUGE
Technical field
The invention relates to an electronic gauge for use with a compressed
gas cylinder and a method of calculating time remaining until substantially
all
gas in a compressed gas cylinder has been depleted. The invention also
relates to a method of monitoring that a residual pressure valve of a gas
cylinder is operational.
Background art
Portable gas cylinders with integrated regulating cylinder valves are
designed to enable patients with respiratory disorders, such as chronic
obstructive pulmonary disease (COPD), to better manage their oxygen
therapy within and outside their homes. COPD alone afflicts hundreds of
million people worldwide on a yearly basis. Supplemental oxygen therapy is
also prescribed for other ailments that weaken the respiratory system, such
as heart disease and AIDS, as well as for asthma and emphysema.
Portable gas cylinders with integrated regulating cylinder valves are
commercially available for providing ambulatory respiratory patients with
COPD and other respiratory ailments with gaseous oxygen. A portable gas
cylinder with integrated regulating cylinder valve holds high pressure oxygen
which is reduced through the regulator to deliver a selectable flow rate. The
portable gas cylinder with integrated regulating cylinder valve is small and
light-weight in order to allow the ambulatory respiratory patient to readily
use
and transport the cylinder inside and outside the home. As a result, the
respiratory patient can lead a more active lifestyle, which in turn can
improve
the overall health of the patient.
A major problem with portable gas cylinders is not knowing the precise
content of gas in order to estimate the time remaining for use with patient.
At
present, the gas cylinders are provided with either a mechanical pressure
gauge or an electronic gauge in order to determine the remaining time of
usage.
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The method remains to have inaccuracies as the temperature of the
gas is not accounted for, nor the variability in flow delivered or the typical
usage pattern for the cylinder. Therefore, the time remaining displayed on
current electronic gauges for medical oxygen gas cylinders are known to be
inaccurate.
Another problem with currently available electronic gauges is their cost.
The price of the electronic gauge in their current format is much higher than
the price of a gas cylinder valve.
Another problem with currently available electronic gauges is that they
cannot be fitted to current gas cylinders in the field.
Summary of the invention
It is an objective of the present invention to mitigate, alleviate or
eliminate one or more of the above-identified deficiencies in the art and
disadvantages singly or in any combination and solve at least the above
mentioned problems.
According to a first aspect of the invention, these and other objects,
and/or advantages that will be apparent from the following description of
embodiments, are achieved, in full or at least in part, by an electronic gauge
for use with a compressed gas cylinder. The electronic gauge comprises a
display interface, a pressure sensor having a pressure sensing element and
an amplification circuit for amplifying a signal from the pressure sensing
element, a temperature sensor, and a control electronics board connected to
the display interface, the pressure sensing element and the temperature
sensor. The amplification circuit is integrally formed with the control
electronics board.
This is advantageous in that this type of combination design will
integrate separate elements of the electronic gauge resulting in lower cost
solution. An electronic gauge basically consists of the following elements: a
pressure transmitter, a control electronics board, a display, a battery and a
case. The control electronics and display are contained in a case, often
including the battery. The pressure transmitter is connected to case using a
cable and connector. The new electronic gauge design integrates the
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pressure transmitter into the case. To achieve this the pressure transmitter
is
first separated into its sensing element and its amplification circuit.
Thereafter,
the amplification circuit is integrated onto the control electronics board.
This
enables the whole system to be integrated into the case design such that it is
one complete unit. In doing so costs are significantly reduced regarding the
pressure transmitter through removal of electronics, removal of cables and
connectors, and a reduction in housing design.
The pressure sensing element of the pressure sensor and a
temperature sensing element of the temperature sensor may be adjacently
arranged so as to measure pressure and temperature at the same location.
The electronic gauge may further comprise a memory connected to the
control electronics board.
The electronic gauge may further comprise a casing which houses all
components of the electronic gauge.
The casing may further house a battery providing power to the
components of the electronic gauge.
According to a second aspect of the invention, these and other objects
are achieved, in full or at least in part, by a method of calculating time
remaining until substantially all gas in a compressed gas cylinder has been
depleted. The method comprises detecting an open flowrate position of the
gas cylinder, detecting at least one pressure value in the gas cylinder,
detecting at least one temperature value in the gas cylinder, and calculating
a
time remaining until substantially all gas in a compressed gas cylinder has
been depleted based on the at least one pressure value, the at least one
temperature value, and a volume of the gas cylinder. The at least one
pressure value and the at least one temperature value are detected at the
same location.
As stated above, the problem with currently available methods for
calculating the time remaining is especially that they have inaccuracies as
the
temperature of the gas is not accounted for. This is a known and recognised
problem that attempts have been made to be solved by using temperature
measurement at the electronics board. This unfortunately often does not
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accurately reflect the real temperature of the gas, for example during filling
when adiabatic compression occurs.
The second aspect of the invention provides a method for an accurate
measure of pressure and temperature along with an accurate sensing of the
flow selector position. This is achieved by detecting the pressure and
temperature at the same time and location.
The method may further comprise displaying the time remaining until
substantially all gas in the gas cylinder has been depleted on a display
interface.
The method may further comprise storing the detected values which in
connection with a learning algorithm is used to enhance the accuracy in
calculating the time remaining until substantially all gas in a compressed gas
cylinder has been depleted.
The method may further comprise triggering an alarm if the calculated
time remaining until substantially all gas in a compressed gas cylinder has
been depleted is below a predetermined time value.
The method may further comprise wirelessly sending a signal to a
further unit upon triggering of the alarm.
According to a third aspect of the invention, these and other objects
are achieved, in full or at least in part, by a method of monitoring that a
residual pressure valve of a gas cylinder is operational. The method
comprises detecting at least one pressure value in the gas cylinder, detecting
at least one temperature value in the gas cylinder, detecting an open flowrate
position of the residual pressure valve, calculating an activation pressure of
the residual pressure valve based on the at least one temperature value,
comparing the at least one pressure value in the gas cylinder with the
calculated activation pressure of the residual pressure valve, and indicating
to
a user that the residual pressure valve is operational if the detected at
least
one pressure value is above the calculated activation pressure for a specific
time period, and/or indicating to the user that the residual pressure valve is
not operational if the detected at least one pressure value is below the
calculated activation pressure for a specific time period.
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This is advantageous in that the method is able to accurately measure
the pressure and temperature in the cylinder and identify if the residual
pressure valve has operated and if it has operated successfully. This is
achieved by monitoring the flowrate position (i.e. open so gas should flow)
5 and the pressure of the cylinder. If, at the activation pressure of the
residual
pressure valve, the pressure remains stable then the residual pressure valve
is working. If the valve is open and the pressure continues to decrease below
the activation pressure at a rate greater than temperature effects (i.e.
cooling), then it can be identified that the residual pressure valve is not
working. This can then be displayed and wirelessly transmitted so that the
gas re-filler knows the valve requires repair or maintenance. If, in any state
the pressure is measured to be below the activation pressure of the residual
pressure valve, it can be identified, displayed and wirelessly transmitted so
that the gas re-filler knows the valve requires repair or maintenance.
Further,
the historical functioning of the residual pressure valve can be monitored in
terms of how many times it has been activated and at what pressure it did
activate. With this information predictive maintenance of the residual
pressure
can be conducted.
The at least one pressure value and the at least one temperature value
may be detected at the same location.
The steps of the method may be repeated continuously such that a
constant indication of the status of the residual pressure valve can be
provided.
The method may further comprise storing any information relating to
the residual pressure valve on a memory. Further the historical functioning of
the residual pressure valve can be monitored in terms of how many times it
has been activated and at what pressure it did activate. With this information
predictive maintenance of the residual pressure can be conducted.
The method may further comprise presenting the indication of the
status of the residual pressure valve on a display interface and/or wirelessly
transmitting the indication of the status of the residual pressure valve to a
further unit.
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Effects and features of the second and the third aspect of the present
invention are largely analogous to those described above in connection with
the first aspect of the inventive concept. Embodiments mentioned in relation
to the first aspect of the present invention are largely compatible with the
further aspects of the invention.
Other objectives, features and advantages of the present invention will
appear from the following detailed disclosure, from the attached claims, as
well as from the drawings. It is noted that the invention relates to all
possible
combinations of features.
Generally, all terms used in the claims are to be interpreted according
to their ordinary meaning in the technical field, unless explicitly defined
otherwise herein. All references to "a/an/the [element, device, component,
means, step, etc.]" are to be interpreted openly as referring to at least one
instance of the element, device, component, means, step, etc., unless
explicitly stated otherwise.
As used herein, the term "comprising" and variations of that term are
not intended to exclude other additives, components, integers or steps.
Brief description of the drawings
The above, as well as additional objects, features and advantages of
the present invention, will be better understood through the following
illustrative and non-limiting detailed description of embodiments of the
present
invention, with reference to the appended drawings, where the same
reference numerals may be used for similar elements, and wherein:
Fig. 1A and 1B are perspective views of an exemplary embodiment of
an electronic gauge according to first aspect of the invention.
Fig. 2A to 2B are perspective views of an exemplary embodiment of
a gas cylinder equipped with the electronic gauge in Fig. 1A and 1B.
Fig. 3 is a perspective view of a system including the electronic gauge
in Fig. 1A and 1B.
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Detailed description of preferred embodiments of the invention
Fig. 1A and 1 B illustrate an exemplary embodiment of an electronic
gauge 1 for use with a compressed gas cylinder 2. The electronic gauge 1
comprises a display interface 4, a pressure sensor 5 which divided into a
pressure sensing element 6 and an amplification circuit 7 for amplifying a
signal from the pressure sensing element 6, and a temperature sensor 8. The
pressure sensing element 6 of the pressure sensor 7 and a temperature
sensing element 9 of the temperature sensor 8 are adjacently arranged so as
to be able to measure pressure and temperature at the same location in the
gas cylinder 2.
The electronic gauge 1 further comprises a control electronics board
10 which is connected to the display interface 4, the pressure sensing
element 6 and the temperature sensor 8. The amplification circuit 7 is
integrally formed with the control electronics board 10 in order to be able to
make a more compact overall electronic gauge 1. In this specific embodiment,
the electronic gauge 1 is further equipped with a memory 11 which also is
connected to the control electronics board 10.
Here, an outer casing 12 is provided which houses all components of
the electronic gauge 1. The outer casing 12 comprises a battery 13 which
provides power to the components of the electronic gauge 1.
Fig. 2A and 2B illustrate the gas cylinder 2 equipped with the electronic
gauge 1 of the present invention.
The new and inventive electronic gauge 1 is useful in a number of
different ways, both for a user of the gas cylinder 2 as well as for a patient
caretaker.
According to one exemplary method, the electronic gauge 1 is used to
calculate the time remaining until substantially all gas in the gas cylinder 2
has been depleted.
The method comprises detecting an open flowrate position of the gas
cylinder 2, detecting at least one pressure value in the gas cylinder 2,
detecting at least one temperature value in the gas cylinder 2, and
calculating a time remaining until substantially all gas in a compressed gas
cylinder 2 has been depleted based on the at least one pressure value, the at
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least one temperature value, and a volume of the gas cylinder. The at least
one pressure value and the at least one temperature value are detected at
the same location in the gas cylinder 2.
In one preferred embodiment, the method further comprises storing the
detected values which in connection with a learning algorithm is used to
enhance the accuracy in calculating the time remaining until substantially all
gas in a compressed gas cylinder 2 has been depleted.
The method could also include displaying the time remaining until
substantially all gas in the gas cylinder 2 has been depleted on a display
interface, and triggering an alarm if the calculated time remaining until
substantially all gas in a compressed gas cylinder 2 has been depleted is
below a predetermined time value. Preferably, a signal to a display unit 14 is
sent wirelessly upon triggering of the alarm.
According to another exemplary method, the electronic gauge 1 is
used to monitor that a residual pressure valve (not shown) of the gas cylinder
2 is operational.
The method comprises detecting at least one pressure value in the gas
cylinder 2, detecting at least one temperature value in the gas cylinder 2,
detecting an open flowrate position of the residual pressure valve,
calculating
an activation pressure of the residual pressure valve based on the at least
one temperature value, comparing the at least one pressure value in the gas
cylinder 2 with the calculated activation pressure of the residual pressure
valve, and indicating to a user that the residual pressure valve is
operational if
the detected at least one pressure value is above the calculated activation
pressure for a specific time period, and/or indicating to the user that the
residual pressure valve is not operational if the detected at least one
pressure
value is below the calculated activation pressure for a specific time period.
Preferably, the at least one pressure value and the at least one
temperature value are detected at the same location.
Further, in order to be able to provide a continuous monitoring of the
status of the residual pressure valve, the steps of the method are repeated
continuously such that a constant indication of the status of the residual
pressure valve can be provided.
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The method could also comprise storing any information relating to the
residual pressure valve on the memory 11, and comprising presenting the
indication of the status of the residual pressure valve on a display interface
and/or wirelessly transmitting the indication of the status of the residual
pressure valve to a further unit 14.
Fig. 3 illustrates a system in which the gas cylinder 2 equipped with the
electronic gauge 1 is wirelessly connected to the display unit 14 via a cloud.
The signal from the electronic gauge 1 goes through a hub using Bluetooth
which in turn transmits the data. An oxygen concentrator may be used as the
hub, or it be constituted by a stand-alone hub in order to thereafter link to
the
cloud or any other data transmission.
It is understood that other variations in the present invention are
contemplated and in some instances, some features of the invention can be
employed without a corresponding use of other features. Accordingly, it is
appropriate that the appended claims be construed broadly in a manner
consistent with the scope of the invention.
Naturally, the number, size and shape of the components of the
electronic gauge 1 may be variated in any suitable way without departing from
the scope of the invention.
The control electronics board 10 may be programmed to initiate
different types of alarms in order to make the gas cylinder 2 more user-
friendly and to enhance safety related to the use of the same. The control
electronics board 10 may for example be programmed to initiate an alarm if
the pressure sensor 5 or the temperature sensor 8 detect values outside of a
predetermined range. Another example could be an alarm for no flow, i.e. if
the flow knob is set to give a flow but the shutoff valve is off, an alarm
should
be initiated after about 30 seconds once the electronic gauge 1 has
established that there is no pressure drop.
